The Paraná Senate race for two seats on October 4 remains tightly contested among Alexandre Curi, Deltan Dallagnol, Filipe Barros, and Gleisi Hoffmann, with recent polls showing them clustered in the low double digits amid high undecided shares and a fragmented right-wing field. Curi benefits from Republican backing and state legislative ties, while Dallagnol and Barros share a Novo-PL alliance linked to Sergio Moro's gubernatorial bid; Gleisi draws PT support as a national figure. Candidate eligibility rulings by the electoral court, right-wing vote splitting across multiple names, and the absence of incumbents seeking reelection sustain the uncertainty reflected in current trader pricing. Late polling shifts or court decisions on pending candidacies could separate the leaders before voting.